Deutsche Oper’s admin block sits along an unassuming Berlin side street off the city’s westward artery Bismarckstraße. The street sign reads Richard-Wagner-Straße, which rather suggests that the Edinburgh-born conductor Sir Donald Runnicles, approaching his 70th birthday in November, has absolutely been living his dream. For Runnicles has always considered a 1971 George Watson’s College school trip to see Wagner’s Das Rheingold - part of Scottish Opera’s legendary 1970s’ Ring cycle - as the epiphany that shaped his operatic career.

And here he is, 15 years into his celebrated tenure as general musical director of Germany’s flagship opera company, with his hero greeting him each day at work. “It’s been a personal satisfaction to have the scores that are regularly sent to me from around the world labelled to this address,” he chuckles, visibly “at home” in his spacious office behind a score-filled desk, dressed casually in shorts and trainers. It’s a sweltering April afternoon, a production is in preparation next door, and guess what, it’s another Ring opener.

But not with Runnicles in charge. He directed the full cycle last year. This time he’s happy to hand over the reins to a younger Australian conductor he seriously rates, Nicholas Carter.

Nonetheless, Wagner’s spirit seems to be lurking everywhere. Runnicles’ own Ring tally is “in the 40s now”, he reckons. It’s what brought him to the notice of Deutsche Oper.

“I guested here in 2.